﻿/*
 * Copyright (c) 2009, Thiago M. Sayao <thiago.sayao@gmail.com>
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 *  * Redistributions of source code must retain the above copyright notice, 
 *    this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *  * Neither the name of the author nor the names of its contributors may be 
 *    used to endorse or promote products derived from this software without 
 *    specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using DotNetBurner.Core;

namespace DotNetBurner.Web
{
    public static class Trackback
    {
        public static void Send(string remoteUrl, string storyTitle, string storyUrl, string message, 
                                string siteName, string category)
        {
            string postParams = String.Format("title={0}&url={1}&excerpt={2}&blog_name={3}",
                                              Encode(storyTitle),
                                              Encode(storyUrl),
                                              Encode(message),
                                              Encode(String.Format("{0} - {1}", siteName, category)));

            BeginGetDataFromUrl(remoteUrl, postParams);
        }

        static string Encode(string input) 
        {
	        string ret = input.Replace("\"", "'").UrlEncode();

            return ret.Replace("%2f", "/");
        }

        static void BeginGetDataFromUrl(string url, string postParams)
        {
           AsyncCallback cb = new AsyncCallback(delegate(IAsyncResult result)
           {
               //this will be called when WebUtility.BeginGetDataFromUrl finishes
               string html = WebUtility.EndGetDataFromUrl(result);

               //get the trackbackUrl
               HtmlUtil htmlUtil = new HtmlUtil(html);
               string trackbackUrl = htmlUtil.GetTrackbackUrl(url);

               //trackback is not null, so send the form post
               if (!string.IsNullOrEmpty(trackbackUrl) && trackbackUrl.IsValidUrl())
                   WebUtility.SendPostDataAsync(trackbackUrl, postParams);
           });

           WebUtility.BeginGetDataFromUrl(cb, null, url);
        }
    }
}
